ABC News -- Jake Tapper and Yunji de Nies report: Its unclear which White House staffer thought it would be a good idea to have an NBC show called The Biggest Loser visit the White House in an episode that aired on what was shaping up to be a tough election night for President Obama and the Democratic party, but the contestants stopped by 1600 Pennsylvania Avenue Tuesday night as election returns came in. The segment featured the contestants overweight folks trying desperately to lose weight -- harvesting vegetables in First Lady Michelle Obama's White House Kitchen Garden, with the help of assistant chef Sam Kass. The gang then went into the kitchen and made a big salad. The contestants and the hosts lavished praise on the Obamas for setting a...